summaryrefslogtreecommitdiff
path: root/saveload.c
blob: b120f05352142fe4a74edbe8f57d480099532787 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
/** @file
 * All actions handling saving and loading goes on in this file. The general actions
 * are as follows for saving a game (loading is analogous):
 * <ol>
 * <li>initialize the writer by creating a temporary memory-buffer for it
 * <li>go through all to-be saved elements, each 'chunk' (ChunkHandler) prefixed by a label
 * <li>use their description array (SaveLoad) to know what elements to save and in what version
 *    of the game it was active (used when loading)
 * <li>write all data byte-by-byte to the temporary buffer so it is endian-safe
 * <li>when the buffer is full; flush it to the output (eg save to file) (_sl.buf, _sl.bufp, _sl.bufe)
 * <li>repeat this until everything is done, and flush any remaining output to file
 * </ol>
 * @see ChunkHandler
 * @see SaveLoad
 */
#include "stdafx.h"
#include "openttd.h"
#include "debug.h"
#include "vehicle.h"
#include "station.h"
#include "town.h"
#include "player.h"
#include "saveload.h"

enum {
	SAVEGAME_MAJOR_VERSION = 15,
	SAVEGAME_MINOR_VERSION = 0,

	SAVEGAME_LOADABLE_VERSION = (SAVEGAME_MAJOR_VERSION << 8) + SAVEGAME_MINOR_VERSION
};

enum NeedLengthValues {NL_NONE = 0, NL_WANTLENGTH = 1, NL_CALCLENGTH = 2};

SaverLoader _sl;

/**
 * Fill the input buffer by reading from the file with the given reader
 */
static void SlReadFill(void)
{
	uint len = _sl.read_bytes();
	assert(len != 0);

	_sl.bufp = _sl.buf;
	_sl.bufe = _sl.buf + len;
	_sl.offs_base += len;
}

static inline uint32 SlGetOffs(void) {return _sl.offs_base - (_sl.bufe - _sl.bufp);}

/** Flush the output buffer by writing to disk with the given reader.
 * If the buffer pointer has not yet been set up, set it up now. Usually
 * only called when the buffer is full, or there is no more data to be processed
 */
static void SlWriteFill(void)
{
	// flush the buffer to disk (the writer)
	if (_sl.bufp != NULL) {
		uint len = _sl.bufp - _sl.buf;
		_sl.offs_base += len;
		if (len) _sl.write_bytes(len);
	}

	/* All the data from the buffer has been written away, rewind to the beginning
	* to start reading in more data */
	_sl.bufp = _sl.buf;
	_sl.bufe = _sl.buf + _sl.bufsize;
}

/** Error handler, calls longjmp to simulate an exception.
 * @todo this was used to have a central place to handle errors, but it is
 * pretty ugly, and seriously interferes with any multithreaded approaches */
static void NORETURN SlError(const char *msg)
{
	_sl.excpt_msg = msg;
	longjmp(_sl.excpt, 0);
}

/** Read in a single byte from file. If the temporary buffer is full,
 * flush it to its final destination
 * @return return the read byte from file
 */
static inline int SlReadByteInternal(void)
{
	if (_sl.bufp == _sl.bufe) SlReadFill();
	return *_sl.bufp++;
}

/** Wrapper for SlReadByteInternal */
int SlReadByte(void) {return SlReadByteInternal();}

/** Write away a single byte from memory. If the temporary buffer is full,
 * flush it to its destination (file)
 * @param b the byte that is currently written
 */
static inline void SlWriteByteInternal(byte b)
{
	if (_sl.bufp == _sl.bufe) SlWriteFill();
	*_sl.bufp++ = b;
}

/** Wrapper for SlWriteByteInternal */
void SlWriteByte(byte b) {SlWriteByteInternal(b);}

static inline int SlReadUint16(void)
{
	int x = SlReadByte() << 8;
	return x | SlReadByte();
}

static inline uint32 SlReadUint32(void)
{
	uint32 x = SlReadUint16() << 16;
	return x | SlReadUint16();
}

static inline uint64 SlReadUint64(void)
{
	uint32 x = SlReadUint32();
	uint32 y = SlReadUint32();
	return (uint64)x << 32 | y;
}

static inline void SlWriteUint16(VarType v)
{
	SlWriteByte((byte)(v >> 8));
	SlWriteByte((byte)v);
}

static inline void SlWriteUint32(uint32 v)
{
	SlWriteUint16((uint16)(v >> 16));
	SlWriteUint16((uint16)v);
}

static inline void SlWriteUint64(uint64 x)
{
	SlWriteUint32((uint32)(x >> 32));
	SlWriteUint32((uint32)x);
}

/**
 * Read in the header descriptor of an object or an array.
 * If the highest bit is set (7), then the index is bigger than 127
 * elements, so use the next byte to read in the real value.
 * The actual value is then both bytes added with the first shifted
 * 8 bits to the left, and dropping the highest bit (which only indicated a big index).
 * x = ((x & 0x7F) << 8) + SlReadByte();
 * @return Return the value of the index
 */
static uint SlReadSimpleGamma(void)
{
	uint i = SlReadByte();
	if (HASBIT(i, 7)) {
		i &= ~0x80;
		if (HASBIT(i, 6)) {
			i &= ~0x40;
			if (HASBIT(i, 5)) {
				i &= ~0x20;
				if (HASBIT(i, 4))
					SlError("Unsupported gamma");
				i = (i << 8) | SlReadByte();
			}
			i = (i << 8) | SlReadByte();
		}
		i = (i << 8) | SlReadByte();
	}
	return i;
}

/**
 * Write the header descriptor of an object or an array.
 * If the element is bigger than 127, use 2 bytes for saving
 * and use the highest byte of the first written one as a notice
 * that the length consists of 2 bytes, etc.. like this:
 * 0xxxxxxx
 * 10xxxxxx xxxxxxxx
 * 110xxxxx xxxxxxxx xxxxxxxx
 * 1110xxxx xxxxxxxx xxxxxxxx xxxxxxxx
 * @param i Index being written
 */

static void SlWriteSimpleGamma(uint i)
{
	if (i >= (1 << 7)) {
		if (i >= (1 << 14)) {
			if (i >= (1 << 21)) {
				assert(i < (1 << 28));
				SlWriteByte((byte)0xE0 | (i>>24));
				SlWriteByte((byte)(i>>16));
			} else {
				SlWriteByte((byte)0xC0 | (i>>16));
			}
			SlWriteByte((byte)(i>>8));
		} else {
			SlWriteByte((byte)(0x80 | (i>>8)));
		}
	}
	SlWriteByte(i);
}

/** Return how many bytes used to encode a gamma value */
static inline uint SlGetGammaLength(uint i) {
	return 1 + (i >= (1 << 7)) + (i >= (1 << 14)) + (i >= (1 << 21));
}

static inline int SlReadSparseIndex(void) {return SlReadSimpleGamma();}
static inline void SlWriteSparseIndex(uint index) {SlWriteSimpleGamma(index);}

static inline int SlReadArrayLength(void) {return SlReadSimpleGamma();}
static inline void SlWriteArrayLength(uint length) {SlWriteSimpleGamma(length);}

void SlSetArrayIndex(uint index)
{
	_sl.need_length = NL_WANTLENGTH;
	_sl.array_index = index;
}

/**
 * Iterate through the elements of an array and read the whole thing
 * @return The index of the object, or -1 if we have reached the end of current block
 */
int SlIterateArray(void)
{
	int index;
	static uint32 next_offs;

	/* After reading in the whole array inside the loop
	 * we must have read in all the data, so we must be at end of current block. */
	assert(next_offs == 0 || SlGetOffs() == next_offs);

	while (true) {
		uint length = SlReadArrayLength();
		if (length == 0) {
			next_offs = 0;
			return -1;
		}

		_sl.obj_len = --length;
		next_offs = SlGetOffs() + length;

		switch (_sl.block_mode) {
		case CH_SPARSE_ARRAY: index = SlReadSparseIndex(); break;
		case CH_ARRAY:        index = _sl.array_index++; break;
		default:
			DEBUG(misc, 0) ("SlIterateArray: error");
			return -1; // error
		}

		if (length != 0) return index;
	}
}

/**
 * Sets the length of either a RIFF object or the number of items in an array.
 * This lets us load an object or an array of arbitrary size
 * @param length The length of the sought object/array
 */
void SlSetLength(size_t length)
{
	switch (_sl.need_length) {
	case NL_WANTLENGTH:
		_sl.need_length = NL_NONE;
		switch (_sl.block_mode) {
		case CH_RIFF:
			// Ugly encoding of >16M RIFF chunks
			// The lower 24 bits are normal
			// The uppermost 4 bits are bits 24:27
			assert(length < (1<<28));
			SlWriteUint32((length & 0xFFFFFF) | ((length >> 24) << 28));
			break;
		case CH_ARRAY:
			assert(_sl.last_array_index <= _sl.array_index);
			while (++_sl.last_array_index <= _sl.array_index)
				SlWriteArrayLength(1);
			SlWriteArrayLength(length + 1);
			break;
		case CH_SPARSE_ARRAY:
			SlWriteArrayLength(length + 1 + SlGetGammaLength(_sl.array_index)); // Also include length of sparse index.
			SlWriteSparseIndex(_sl.array_index);
			break;
		default: NOT_REACHED();
		} break;
	case NL_CALCLENGTH:
		_sl.obj_len += length;
		break;
	}
}

/**
 * Save/Load bytes. These do not need to be converted to Little/Big Endian
 * so directly write them or read them to/from file
 * @param ptr The source or destination of the object being manipulated
 * @param length number of bytes this fast CopyBytes lasts
 */
static void SlCopyBytes(void *ptr, size_t length)
{
	byte *p = (byte*)ptr;

	if (_sl.save) {
		for (; length != 0; length--) {SlWriteByteInternal(*p++);}
	} else {
		for (; length != 0; length--) {*p++ = SlReadByteInternal();}
	}
}

#if 0
/**
 * Read in bytes from the file/data structure but don't do
 * anything with them
 * NOTICE: currently unused
 * @param length The amount of bytes that is being treated this way
 */
static inline void SlSkipBytes(size_t length)
{
	for (; length != 0; length--)
		SlReadByte();
}
#endif

/* Get the length of the current object */
uint SlGetFieldLength(void) {return _sl.obj_len;}

/**
 * Handle all conversion and typechecking of variables here.
 * In the case of saving, read in the actual value from the struct
 * and then write them to file, endian safely. Loading a value
 * goes exactly the opposite way
 * @param ptr The object being filled/read
 * @param conv @VarType type of the current element of the struct
 */
static void SlSaveLoadConv(void *ptr, VarType conv)
{
	int64 x = 0;

	if (_sl.save) { /* SAVE values */
		/* Read a value from the struct. These ARE endian safe. */
		switch ((conv >> 4) & 0xF) {
		case SLE_VAR_I8   >> 4: x = *(int8*)ptr; break;
		case SLE_VAR_U8   >> 4: x = *(byte*)ptr; break;
		case SLE_VAR_I16  >> 4: x = *(int16*)ptr; break;
		case SLE_VAR_U16  >> 4: x = *(uint16*)ptr; break;
		case SLE_VAR_I32  >> 4: x = *(int32*)ptr; break;
		case SLE_VAR_U32  >> 4: x = *(uint32*)ptr; break;
		case SLE_VAR_I64  >> 4: x = *(int64*)ptr; break;
		case SLE_VAR_U64  >> 4: x = *(uint64*)ptr; break;
		case SLE_VAR_NULL >> 4: x = 0; break;
		default: NOT_REACHED();
		}

		// Write the value to the file and check if its value is in the desired range
		switch (conv & 0xF) {
		case SLE_FILE_I8: assert(x >= -128 && x <= 127);     SlWriteByte(x);break;
		case SLE_FILE_U8: assert(x >= 0 && x <= 255);        SlWriteByte(x);break;
		case SLE_FILE_I16:assert(x >= -32768 && x <= 32767); SlWriteUint16(x);break;
		case SLE_FILE_STRINGID:
		case SLE_FILE_U16:assert(x >= 0 && x <= 65535);      SlWriteUint16(x);break;
		case SLE_FILE_I32: case SLE_FILE_U32:                SlWriteUint32((uint32)x);break;
		case SLE_FILE_I64: case SLE_FILE_U64:                SlWriteUint64(x);break;
		default: NOT_REACHED();
		}
	} else { /* LOAD values */

		// Read a value from the file
		switch (conv & 0xF) {
		case SLE_FILE_I8:  x = (int8)SlReadByte(); break;
		case SLE_FILE_U8:  x = (byte)SlReadByte(); break;
		case SLE_FILE_I16: x = (int16)SlReadUint16(); break;
		case SLE_FILE_U16: x = (uint16)SlReadUint16(); break;
		case SLE_FILE_I32: x = (int32)SlReadUint32(); break;
		case SLE_FILE_U32: x = (uint32)SlReadUint32(); break;
		case SLE_FILE_I64: x = (int64)SlReadUint64(); break;
		case SLE_FILE_U64: x = (uint64)SlReadUint64(); break;
		case SLE_FILE_STRINGID: x = RemapOldStringID((uint16)SlReadUint16()); break;
		default: NOT_REACHED();
		}

		/* Write The value to the struct. These ARE endian safe. */
		switch ((conv >> 4) & 0xF) {
		case SLE_VAR_I8   >> 4:  *(int8*)ptr = x; break;
		case SLE_VAR_U8   >> 4:  *(byte*)ptr = x; break;
		case SLE_VAR_I16  >> 4: *(int16*)ptr = x; break;
		case SLE_VAR_U16  >> 4: *(uint16*)ptr = x; break;
		case SLE_VAR_I32  >> 4: *(int32*)ptr = x; break;
		case SLE_VAR_U32  >> 4: *(uint32*)ptr = x; break;
		case SLE_VAR_I64  >> 4: *(int64*)ptr = x; break;
		case SLE_VAR_U64  >> 4: *(uint64*)ptr = x; break;
		case SLE_VAR_NULL >> 4: break;
		default: NOT_REACHED();
		}
	}
}

/* Length in bytes of the various datatypes in a savefile. These
 * sizes are guaranteed by assert_compiles in stdafx.h */
static const byte _conv_lengths[] = {1, 1, 2, 2, 4, 4, 8, 8, 2};

/**
 * Return the size in bytes of a certain type of normal/atomic variable
 * @param var The variable the size is being asked of (NOTICE: unused)
 * @param conv @VarType type of variable that is used for calculating the size
 * @return Return the size of this type in byes
 */
static inline size_t SlCalcConvLen(const void *var, VarType conv) {return _conv_lengths[conv & 0xF];}

/**
 * Return the size in bytes of a reference (pointer)
 */
static inline size_t SlCalcRefLen(void) {return 2;}

/**
 * Return the size in bytes of a certain type of atomic array
 * @param array The variable the size is being asked of (NOTICE: unused)
 * @param length The length of the array counted in elements
 * @param conv @VarType type of the variable that is used in calculating the size
 */
static inline size_t SlCalcArrayLen(const void *array, uint length, VarType conv) {return _conv_lengths[conv & 0xF] * length;}

/**
 * Save/Load an array.
 * @param array The array being manipulated
 * @param length The length of the array in elements
 * @param conv @VarType type of the atomic array (int, byte, uint64, etc.)
 */
void SlArray(void *array, uint length, VarType conv)
{
	static const byte conv_mem_size[] = {1, 1, 2, 2, 4, 4, 8, 8, 0};

	// Automatically calculate the length?
	if (_sl.need_length != NL_NONE) {
		SlSetLength(SlCalcArrayLen(array, length, conv));
		// Determine length only?
		if (_sl.need_length == NL_CALCLENGTH)
			return;
	}

	/* NOTICE - handle some buggy stuff, in really old versions everything was saved
	 * as a byte-type. So detect this, and adjust array size accordingly */
	if (!_sl.save && _sl.version == 0) {
		if (conv == SLE_INT16 || conv == SLE_UINT16 || conv == SLE_STRINGID) {
			length *= 2; // int16, uint16 and StringID are 2 bytes in size
			conv = SLE_INT8;
		} else if (conv == SLE_INT32 || conv == SLE_UINT32) {
			length *= 4; // int32 and uint32 are 4 bytes in size
			conv = SLE_INT8;
		}
	}

	/* If the size of elements is 1 byte, no special conversion is needed,
	 * use specialized copy-to-copy function to speed up things */
	if (conv == SLE_INT8 || conv == SLE_UINT8) {
		SlCopyBytes(array, length);
	} else {
		byte *a = (byte*)array;
		for (; length != 0; length --) {
			SlSaveLoadConv(a, conv);
			a += conv_mem_size[(conv >> 4) & 0xF]; // get size
		}
	}
}

/**
 * Calculate the size of an object.
 * @param object Object that needs its length calculated
 * @param sld The @SaveLoad description of the object so we know how to manipulate it
 */
static size_t SlCalcObjLength(void *object, const SaveLoad *sld)
{
	size_t length = 0;

	// Need to determine the length and write a length tag.
	for (; sld->cmd != SL_END; sld++) {
		if (sld->cmd < SL_WRITEBYTE) {
			if (HASBIT(sld->cmd, 2)) {
				// check if the field is used in the current savegame version
				if (_sl.version < sld->version_from || _sl.version > sld->version_to)
					continue;
			}

			switch (sld->cmd) {
			case SL_VAR: case SL_CONDVAR: /* Normal Variable */
				length += SlCalcConvLen(NULL, sld->type); break;
			case SL_REF: case SL_CONDREF:  /* Reference variable */
				length += SlCalcRefLen(); break;
			case SL_ARR: case SL_CONDARR: /* Array */
				length += SlCalcArrayLen(NULL, sld->length, sld->type); break;
			default: NOT_REACHED();
			}
		} else if (sld->cmd == SL_WRITEBYTE) {
			length++; // a byte is logically of size 1
		} else if (sld->cmd == SL_INCLUDE) {
			length += SlCalcObjLength(NULL, _sl.includes[sld->version_from]);
		} else
			assert(sld->cmd == SL_END);
	}
	return length;
}

/**
 * Main SaveLoad function.
 * @param object The object that is being saved or loaded
 * @param sld The @SaveLoad description of the object so we know how to manipulate it
 */
void SlObject(void *object, const SaveLoad *sld)
{
	// Automatically calculate the length?
	if (_sl.need_length != NL_NONE) {
		SlSetLength(SlCalcObjLength(object, sld));
		if (_sl.need_length == NL_CALCLENGTH)
			return;
	}

	for (; sld->cmd != SL_END; sld++) {
		void *ptr = (byte*)object + sld->offset;

		if (sld->cmd < SL_WRITEBYTE) {
			/* CONDITIONAL saveload types depend on the savegame version */
			if (HASBIT(sld->cmd, 2)) {
				// check if the field is of the right version, if not, proceed to next one
				if (_sl.version < sld->version_from || _sl.version > sld->version_to)
					continue;
			}

			switch (sld->cmd) {
			case SL_VAR: case SL_CONDVAR: /* Normal variable */
				SlSaveLoadConv(ptr, sld->type); break;
			case SL_REF: case SL_CONDREF: /* Reference variable, translate */
				/// @todo XXX - another artificial limitof 65K elements of pointers?
				if (_sl.save) { // XXX - read/write pointer as uint16? What is with higher indeces?
					SlWriteUint16(_sl.ref_to_int_proc(*(void**)ptr, sld->type));
				} else
					*(void**)ptr = _sl.int_to_ref_proc(SlReadUint16(), sld->type);
				break;
			case SL_ARR: case SL_CONDARR: /* Array */
				SlArray(ptr, sld->length, sld->type); break;
			default: NOT_REACHED();
			}

		/* SL_WRITEBYTE translates a value of a variable to another one upon
		 * saving or loading.
		 * XXX - variable renaming abuse
		 * g_value: the value of the variable ingame is abused by sld->version_from
		 * f_value: the value of the variable in the savegame is abused by sld->version_to */
		} else if (sld->cmd == SL_WRITEBYTE) {
			if (_sl.save) {
				SlWriteByte(sld->version_to);
			} else
				*(byte*)ptr = sld->version_from;
		/* SL_INCLUDE loads common code for a type
		 * XXX - variable renaming abuse
		 * include_index: common code to include from _desc_includes[], abused by sld->version_from */
		} else if (sld->cmd == SL_INCLUDE) {
			SlObject(ptr, _sl.includes[sld->version_from]);
		} else
			assert(sld->cmd == SL_END);
	}
}

/** Calculate the length of global variables
 * @param desc The global variable that we want to know the size of
 * @return Returns the length of the sought global object
 */
static size_t SlCalcGlobListLength(const SaveLoadGlobVarList *desc)
{
	size_t length = 0;

	for (; desc->address != NULL; desc++) {
		// Of course the global variable must exist in the sought savegame version
		if (_sl.version >= desc->from_version && _sl.version <= desc->to_version)
			length += SlCalcConvLen(NULL, desc->conv);
	}
	return length;
}

/**
 * Save or Load (a list of) global variables
 * @param desc The global variable that is being loaded or saved
 */
void SlGlobList(const SaveLoadGlobVarList *desc)
{
	if (_sl.need_length != NL_NONE) {
		SlSetLength(SlCalcGlobListLength(desc));
		if (_sl.need_length == NL_CALCLENGTH)
			return;
	}

	for (; desc->address != NULL; desc++) {
		if (_sl.version >= desc->from_version && _sl.version <= desc->to_version)
			SlSaveLoadConv(desc->address, desc->conv);
	}
}

/**
 * Do something of which I have no idea what it is :P
 * @param proc The callback procedure that is called
 * @param arg The variable that will be used for the callback procedure
 */
void SlAutolength(AutolengthProc *proc, void *arg)
{
	uint32 offs;

	assert(_sl.save);

	// Tell it to calculate the length
	_sl.need_length = NL_CALCLENGTH;
	_sl.obj_len = 0;
	proc(arg);

	// Setup length
	_sl.need_length = NL_WANTLENGTH;
	SlSetLength(_sl.obj_len);

	offs = SlGetOffs() + _sl.obj_len;

	// And write the stuff
	proc(arg);

	assert(offs == SlGetOffs());
}

/**
 * Load a chunk of data (eg vehicles, stations, etc.)
 * @param ch The chunkhandler that will be used for the operation
 */
static void SlLoadChunk(const ChunkHandler *ch)
{
	byte m = SlReadByte();
	size_t len;
	uint32 endoffs;

	_sl.block_mode = m;
	_sl.obj_len = 0;

	switch (m) {
	case CH_ARRAY:
		_sl.array_index = 0;
		ch->load_proc();
		break;
	case CH_SPARSE_ARRAY:
		ch->load_proc();
		break;
	default:
		if ((m & 0xF) == CH_RIFF) {
			// Read length
			len = (SlReadByte() << 16) | ((m >> 4) << 24);
			len += SlReadUint16();
			_sl.obj_len = len;
			endoffs = SlGetOffs() + len;
			ch->load_proc();
			assert(SlGetOffs() == endoffs);
		} else {
			SlError("Invalid chunk type");
		}
		break;
	}
}

/* Stub Chunk handlers to only calculate length and do nothing else */
static ChunkSaveLoadProc *_tmp_proc_1;
static inline void SlStubSaveProc2(void *arg) {_tmp_proc_1();}
static void SlStubSaveProc(void) {SlAutolength(SlStubSaveProc2, NULL);}

/** Save a chunk of data (eg. vehicles, stations, etc.). Each chunk is
 * prefixed by an ID identifying it, followed by data, and terminator where appropiate
 * @param ch The chunkhandler that will be used for the operation
 */
static void SlSaveChunk(const ChunkHandler *ch)
{
	ChunkSaveLoadProc *proc = ch->save_proc;

	SlWriteUint32(ch->id);

	if (ch->flags & CH_AUTO_LENGTH) {
		// Need to calculate the length. Solve that by calling SlAutoLength in the save_proc.
		_tmp_proc_1 = proc;
		proc = SlStubSaveProc;
	}

	_sl.block_mode = ch->flags & CH_TYPE_MASK;
	switch (ch->flags & CH_TYPE_MASK) {
	case CH_RIFF:
		_sl.need_length = NL_WANTLENGTH;
		proc();
		break;
	case CH_ARRAY:
		_sl.last_array_index = 0;
		SlWriteByte(CH_ARRAY);
		proc();
		SlWriteArrayLength(0); // Terminate arrays
		break;
	case CH_SPARSE_ARRAY:
		SlWriteByte(CH_SPARSE_ARRAY);
		proc();
		SlWriteArrayLength(0); // Terminate arrays
		break;
	default: NOT_REACHED();
	}
}

/** Save all chunks */
static void SlSaveChunks(void)
{
	const ChunkHandler *ch;
	const ChunkHandler* const *chsc;
	uint p;

	for (p = 0; p != CH_NUM_PRI_LEVELS; p++) {
		for (chsc = _sl.chs; (ch = *chsc++) != NULL;) {
			while (true) {
				if (((ch->flags >> CH_PRI_SHL) & (CH_NUM_PRI_LEVELS - 1)) == p)
					SlSaveChunk(ch);
				if (ch->flags & CH_LAST)
					break;
				ch++;
			}
		}
	}

	// Terminator
	SlWriteUint32(0);
}

/** Find the ChunkHandler that will be used for processing the found
 * chunk in the savegame or in memory
 * @param id the chunk in question
 * @return returns the appropiate chunkhandler
 */
static const ChunkHandler *SlFindChunkHandler(uint32 id)
{
	const ChunkHandler *ch;
	const ChunkHandler *const *chsc;
	for (chsc = _sl.chs; (ch=*chsc++) != NULL;) {
		while(true) {
			if (ch->id == id)
				return ch;
			if (ch->flags & CH_LAST)
				break;
			ch++;
		}
	}
	return NULL;
}

/** Load all chunks */
static void SlLoadChunks(void)
{
	uint32 id;
	const ChunkHandler *ch;

	for (id = SlReadUint32(); id != 0; id = SlReadUint32()) {
		DEBUG(misc, 1) ("Loading chunk %c%c%c%c", id >> 24, id>>16, id>>8, id);

		ch = SlFindChunkHandler(id);
		if (ch == NULL) SlError("found unknown tag in savegame (sync error)");
		SlLoadChunk(ch);
	}
}

//*******************************************
//********** START OF LZO CODE **************
//*******************************************
#define LZO_SIZE 8192

#include "minilzo.h"

static uint ReadLZO(void)
{
	byte out[LZO_SIZE + LZO_SIZE / 64 + 16 + 3 + 8];
	uint32 tmp[2];
	uint32 size;
	uint len;

	// Read header
	if (fread(tmp, sizeof(tmp), 1, _sl.fh) != 1) SlError("file read failed");

	// Check if size is bad
	((uint32*)out)[0] = size = tmp[1];

	if (_sl.version != 0) {
		tmp[0] = TO_BE32(tmp[0]);
		size = TO_BE32(size);
	}

	if (size >= sizeof(out)) SlError("inconsistent size");

	// Read block
	if (fread(out + sizeof(uint32), size, 1, _sl.fh) != 1) SlError("file read failed");

	// Verify checksum
	if (tmp[0] != lzo_adler32(0, out, size + sizeof(uint32))) SlError("bad checksum");

	// Decompress
	lzo1x_decompress(out + sizeof(uint32)*1, size, _sl.buf, &len, NULL);
	return len;
}

// p contains the pointer to the buffer, len contains the pointer to the length.
// len bytes will be written, p and l will be updated to reflect the next buffer.
static void WriteLZO(uint size)
{
	byte out[LZO_SIZE + LZO_SIZE / 64 + 16 + 3 + 8];
	byte wrkmem[sizeof(byte*)*4096];
	uint outlen;

	lzo1x_1_compress(_sl.buf, size, out + sizeof(uint32)*2, &outlen, wrkmem);
	((uint32*)out)[1] = TO_BE32(outlen);
	((uint32*)out)[0] = TO_BE32(lzo_adler32(0, out + sizeof(uint32), outlen + sizeof(uint32)));
	if (fwrite(out, outlen + sizeof(uint32)*2, 1, _sl.fh) != 1) SlError("file write failed");
}

static bool InitLZO(void)
{
	_sl.bufsize = LZO_SIZE;
	_sl.buf = (byte*)malloc(LZO_SIZE);
	return true;
}

static void UninitLZO(void)
{
	free(_sl.buf);
}

//*********************************************
//******** START OF NOCOMP CODE (uncompressed)*
//*********************************************
static uint ReadNoComp(void)
{
	return fread(_sl.buf, 1, LZO_SIZE, _sl.fh);
}

static void WriteNoComp(uint size)
{
	fwrite(_sl.buf, 1, size, _sl.fh);
}

static bool InitNoComp(void)
{
	_sl.bufsize = LZO_SIZE;
	_sl.buf = (byte*)malloc(LZO_SIZE);
	return true;
}

static void UninitNoComp(void)
{
	free(_sl.buf);
}

//********************************************
//********** START OF MEMORY CODE (in ram)****
//********************************************

enum {
	SAVE_POOL_BLOCK_SIZE_BITS = 17,
	SAVE_POOL_MAX_BLOCKS = 500
};

#include "network.h"
#include "table/strings.h"
#include "table/sprites.h"
#include "gfx.h"
#include "gui.h"

typedef struct ThreadedSave {
	MemoryPool *save;
	uint count;
	bool ff_state;
	bool saveinprogress;
	CursorID cursor;
} ThreadedSave;

/* A maximum size of of 128K * 500 = 64.000KB savegames */
static MemoryPool _save_pool = {"Savegame", SAVE_POOL_MAX_BLOCKS, SAVE_POOL_BLOCK_SIZE_BITS, sizeof(byte), NULL, 0, 0, NULL};
static ThreadedSave _ts;

static bool InitMem(void)
{
	_ts.save = &_save_pool;
	_ts.count = 0;

	CleanPool(_ts.save);
	AddBlockToPool(_ts.save);

	/* A block from the pool is a contigious area of memory, so it is safe to write to it sequentially */
	_sl.bufsize = _ts.save->total_items;
	_sl.buf = (byte*)GetItemFromPool(_ts.save, _ts.count);
	return true;
}

static void UnInitMem(void)
{
	CleanPool(_ts.save);
	_ts.save = NULL;
}

static void WriteMem(uint size)
{
	_ts.count += size;
	/* Allocate new block and new buffer-pointer */
	AddBlockIfNeeded(_ts.save, _ts.count);
	_sl.buf = (byte*)GetItemFromPool(_ts.save, _ts.count);
}

//********************************************
//********** START OF ZLIB CODE **************
//********************************************

#if defined(WITH_ZLIB)
#include <zlib.h>
static z_stream _z;

static bool InitReadZlib(void)
{
	memset(&_z, 0, sizeof(_z));
	if (inflateInit(&_z) != Z_OK) return false;

	_sl.bufsize = 4096;
	_sl.buf = (byte*)malloc(4096 + 4096); // also contains fread buffer
	return true;
}

static uint ReadZlib(void)
{
	int r;

	_z.next_out = _sl.buf;
	_z.avail_out = 4096;

	do {
		// read more bytes from the file?
		if (_z.avail_in == 0) {
			_z.avail_in = fread(_z.next_in = _sl.buf + 4096, 1, 4096, _sl.fh);
		}

		// inflate the data
		r = inflate(&_z, 0);
		if (r == Z_STREAM_END)
			break;

		if (r != Z_OK)
			SlError("inflate() failed");
	} while (_z.avail_out);

	return 4096 - _z.avail_out;
}

static void UninitReadZlib(void)
{
	inflateEnd(&_z);
	free(_sl.buf);
}

static bool InitWriteZlib(void)
{
	memset(&_z, 0, sizeof(_z));
	if (deflateInit(&_z, 6) != Z_OK) return false;

	_sl.bufsize = 4096;
	_sl.buf = (byte*)malloc(4096); // also contains fread buffer
	return true;
}

static void WriteZlibLoop(z_streamp z, byte *p, uint len, int mode)
{
	byte buf[1024]; // output buffer
	int r;
	uint n;
	z->next_in = p;
	z->avail_in = len;
	do {
		z->next_out = buf;
		z->avail_out = sizeof(buf);
		r = deflate(z, mode);
			// bytes were emitted?
		if ((n=sizeof(buf) - z->avail_out) != 0) {
			if (fwrite(buf, n, 1, _sl.fh) != 1) SlError("file write error");
		}
		if (r == Z_STREAM_END)
			break;
		if (r != Z_OK) SlError("zlib returned error code");
	} while (z->avail_in || !z->avail_out);
}

static void WriteZlib(uint len)
{
	WriteZlibLoop(&_z, _sl.buf, len, 0);
}

static void UninitWriteZlib(void)
{
	// flush any pending output.
	if (_sl.fh) WriteZlibLoop(&_z, NULL, 0, Z_FINISH);
	deflateEnd(&_z);
	free(_sl.buf);
}

#endif /* WITH_ZLIB */

//*******************************************
//************* END OF CODE *****************
//*******************************************

// these define the chunks
extern const ChunkHandler _misc_chunk_handlers[];
extern const ChunkHandler _player_chunk_handlers[];
extern const ChunkHandler _veh_chunk_handlers[];
extern const ChunkHandler _waypoint_chunk_handlers[];
extern const ChunkHandler _depot_chunk_handlers[];
extern const ChunkHandler _order_chunk_handlers[];
extern const ChunkHandler _town_chunk_handlers[];
extern const ChunkHandler _sign_chunk_handlers[];
extern const ChunkHandler _station_chunk_handlers[];
extern const ChunkHandler _industry_chunk_handlers[];
extern const ChunkHandler _engine_chunk_handlers[];
extern const ChunkHandler _economy_chunk_handlers[];
extern const ChunkHandler _animated_tile_chunk_handlers[];

static const ChunkHandler * const _chunk_handlers[] = {
	_misc_chunk_handlers,
	_veh_chunk_handlers,
	_waypoint_chunk_handlers,
	_depot_chunk_handlers,
	_order_chunk_handlers,
	_industry_chunk_handlers,
	_economy_chunk_handlers,
	_engine_chunk_handlers,
	_town_chunk_handlers,
	_sign_chunk_handlers,
	_station_chunk_handlers,
	_player_chunk_handlers,
	_animated_tile_chunk_handlers,
	NULL,
};

// used to include a vehicle desc in another desc.
extern const SaveLoad _common_veh_desc[];
static const SaveLoad* const _desc_includes[] = {
	_common_veh_desc
};

/**
 * Pointers cannot be saved to a savegame, so this functions gets
 * the index of the item, and if not available, it hussles with
 * pointers (looks really bad :()
 * Remember that a NULL item has value 0, and all
 * indeces have +1, so vehicle 0 is saved as index 1.
 * @param obj The object that we want to get the index of
 * @param rt @SLRefType type of the object the index is being sought of
 * @return Return the pointer converted to an index of the type pointed to
 */
static uint ReferenceToInt(const void *obj, SLRefType rt)
{
	if (obj == NULL) return 0;

	switch (rt) {
		case REF_VEHICLE_OLD: // Old vehicles we save as new onces
		case REF_VEHICLE: return ((Vehicle *)obj)->index + 1;
		case REF_STATION: return ((Station *)obj)->index + 1;
		case REF_TOWN:    return ((Town *)obj)->index + 1;
		case REF_ORDER:   return ((Order *)obj)->index + 1;
		case REF_ROADSTOPS: return ((RoadStop *)obj)->index + 1;
		default: NOT_REACHED();
	}

	return 0; // avoid compiler warning
}

/**
 * Pointers cannot be loaded from a savegame, so this function
 * gets the index from the savegame and returns the appropiate
 * pointer from the already loaded base.
 * Remember that an index of 0 is a NULL pointer so all indeces
 * are +1 so vehicle 0 is saved as 1.
 * @param index The index that is being converted to a pointer
 * @param rt @SLRefType type of the object the pointer is sought of
 * @return Return the index converted to a pointer of any type
 */
static void *IntToReference(uint index, SLRefType rt)
{
	/* After version 4.3 REF_VEHICLE_OLD is saved as REF_VEHICLE,
	 * and should be loaded like that */
	if (rt == REF_VEHICLE_OLD && _sl.full_version >= ((4 << 8) | 4))
		rt = REF_VEHICLE;

	/* No need to look up NULL pointers, just return immediately */
	if (rt != REF_VEHICLE_OLD && index == 0)
		return NULL;

	index--; // correct for the NULL index

	switch (rt) {
		case REF_ORDER: {
			if (!AddBlockIfNeeded(&_order_pool, index))
				error("Orders: failed loading savegame: too many orders");
			return GetOrder(index);
		}
		case REF_VEHICLE: {
			if (!AddBlockIfNeeded(&_vehicle_pool, index))
				error("Vehicles: failed loading savegame: too many vehicles");
			return GetVehicle(index);
		}
		case REF_STATION: {
			if (!AddBlockIfNeeded(&_station_pool, index))
				error("Stations: failed loading savegame: too many stations");
			return GetStation(index);
		}
		case REF_TOWN: {
			if (!AddBlockIfNeeded(&_town_pool, index))
				error("Towns: failed loading savegame: too many towns");
			return GetTown(index);
		}
		case REF_ROADSTOPS: {
			if (!AddBlockIfNeeded(&_roadstop_pool, index))
				error("RoadStops: failed loading savegame: too many RoadStops");
			return GetRoadStop(index);
		}

		case REF_VEHICLE_OLD: {
			/* Old vehicles were saved differently:
			 * invalid vehicle was 0xFFFF,
			 * and the index was not - 1.. correct for this */
			index++;
			if (index == INVALID_VEHICLE)
				return NULL;

			if (!AddBlockIfNeeded(&_vehicle_pool, index))
				error("Vehicles: failed loading savegame: too many vehicles");
			return GetVehicle(index);
		}
		default: NOT_REACHED();
	}

	return NULL;
}

/** The format for a reader/writer type of a savegame */
typedef struct {
	const char *name;           /// name of the compressor/decompressor (debug-only)
	uint32 tag;                 /// the 4-letter tag by which it is identified in the savegame

	bool (*init_read)(void);    /// function executed upon initalization of the loader
	ReaderProc *reader;         /// function that loads the data from the file
	void (*uninit_read)(void);  /// function executed when reading is finished

	bool (*init_write)(void);   /// function executed upon intialization of the saver
	WriterProc *writer;         /// function that saves the data to the file
	void (*uninit_write)(void); /// function executed when writing is done
} SaveLoadFormat;

static const SaveLoadFormat _saveload_formats[] = {
	{"memory", 0,                NULL,         NULL,       NULL,           InitMem,       WriteMem,    UnInitMem},
	{"lzo",    TO_BE32X('OTTD'), InitLZO,      ReadLZO,    UninitLZO,      InitLZO,       WriteLZO,    UninitLZO},
	{"none",   TO_BE32X('OTTN'), InitNoComp,   ReadNoComp, UninitNoComp,   InitNoComp,    WriteNoComp, UninitNoComp},
#if defined(WITH_ZLIB)
	{"zlib",   TO_BE32X('OTTZ'), InitReadZlib, ReadZlib,   UninitReadZlib, InitWriteZlib, WriteZlib,   UninitWriteZlib},
#else
	{"zlib",   TO_BE32X('OTTZ'), NULL,         NULL,       NULL,           NULL,          NULL,        NULL},
#endif
};

/**
 * Return the savegameformat of the game. Whether it was create with ZLIB compression
 * uncompressed, or another type
 * @param s Name of the savegame format. If NULL it picks the first available one
 * @return Pointer to @SaveLoadFormat struct giving all characteristics of this type of savegame
 */
static const SaveLoadFormat *GetSavegameFormat(const char *s)
{
	const SaveLoadFormat *def = endof(_saveload_formats) - 1;

	// find default savegame format, the highest one with which files can be written
	while (!def->init_write) def--;

	if (s != NULL && s[0] != '\0') {
		const SaveLoadFormat *slf;
		for (slf = &_saveload_formats[0]; slf != endof(_saveload_formats); slf++) {
			if (slf->init_write != NULL && strcmp(s, slf->name) == 0)
				return slf;
		}

		ShowInfoF("Savegame format '%s' is not available. Reverting to '%s'.", s, def->name);
	}
	return def;
}

// actual loader/saver function
void InitializeGame(uint log_x, uint log_y);
extern bool AfterLoadGame(uint version);
extern void BeforeSaveGame(void);
extern bool LoadOldSaveGame(const char *file);

/** Small helper function to close the to be loaded savegame an signal error */
static inline int AbortSaveLoad(void)
{
	if (_sl.fh != NULL) fclose(_sl.fh);

	_sl.fh = NULL;
	return SL_ERROR;
}

/** Update the gui accordingly when starting saving
 * and set locks on saveload. Also turn off fast-forward cause with that
 * saving takes Aaaaages */
static inline void SaveFileStart(void)
{
	_ts.ff_state = _fast_forward;
	_fast_forward = false;
	if (_cursor.sprite == SPR_CURSOR_MOUSE) SetMouseCursor(SPR_CURSOR_ZZZ);

	SendWindowMessage(WC_STATUS_BAR, 0, true, 0, 0);
	_ts.saveinprogress = true;
}

/** Update the gui accordingly when saving is done and release locks
 * on saveload */
static inline void SaveFileDone(void)
{
	_fast_forward = _ts.ff_state;
	if (_cursor.sprite == SPR_CURSOR_ZZZ) SetMouseCursor(SPR_CURSOR_MOUSE);

	SendWindowMessage(WC_STATUS_BAR, 0, false, 0, 0);
	_ts.saveinprogress = false;
}

/** We have written the whole game into memory, _save_pool, now find
 * and appropiate compressor and start writing to file.
 */
static bool SaveFileToDisk(void *ptr)
{
	const SaveLoadFormat *fmt = GetSavegameFormat(_savegame_format);
	/* XXX - backup _sl.buf cause it is used internally by the writer
	 * and we update it for our own purposes */
	byte *tmp = _sl.buf;
	uint32 hdr[2];

	SaveFileStart();

	/* XXX - Setup setjmp error handler if an error occurs anywhere deep during
	 * loading/saving execute a longjmp() and continue execution here */
	if (setjmp(_sl.excpt)) {
		AbortSaveLoad();
		_sl.buf = tmp;
		_sl.excpt_uninit();

		ShowInfoF("Save game failed: %s.", _sl.excpt_msg);
		ShowErrorMessage(STR_4007_GAME_SAVE_FAILED, STR_NULL, 0, 0);

		SaveFileDone();
		return false;
	}

	/* We have written our stuff to memory, now write it to file! */
	hdr[0] = fmt->tag;
	hdr[1] = TO_BE32((SAVEGAME_MAJOR_VERSION << 16) + (SAVEGAME_MINOR_VERSION << 8));
	if (fwrite(hdr, sizeof(hdr), 1, _sl.fh) != 1) SlError("file write failed");

	if (!fmt->init_write()) SlError("cannot initialize compressor");
	tmp = _sl.buf; // XXX - init_write can change _sl.buf, so update it

	{
		uint i;
		uint count = 1 << _ts.save->block_size_bits;

		assert(_ts.count == _sl.offs_base);
		for (i = 0; i != _ts.save->current_blocks - 1; i++) {
			_sl.buf = _ts.save->blocks[i];
			fmt->writer(count);
		}

		/* The last block is (almost) always not fully filled, so only write away
		 * as much data as it is in there */
		_sl.buf = _ts.save->blocks[i];
		fmt->writer(_ts.count - (i * count));

		_sl.buf = tmp; // XXX - reset _sl.buf to its original value to let it continue its internal usage
	}

	fmt->uninit_write();
	assert(_ts.count == _sl.offs_base);
	GetSavegameFormat("memory")->uninit_write(); // clean the memorypool
	fclose(_sl.fh);

	SaveFileDone();
	CloseOTTDThread();
	return true;
}

/**
 * Main Save or Load function where the high-level saveload functions are
 * handled. It opens the savegame, selects format and checks versions
 * @param filename The name of the savegame being created/loaded
 * @param mode Save or load. Load can also be a TTD(Patch) game. Use SL_LOAD, SL_OLD_LOAD or SL_SAVE
 * @return Return the results of the action. SL_OK, SL_ERROR or SL_REINIT ("unload" the game)
 */
int SaveOrLoad(const char *filename, int mode)
{
	uint32 hdr[2];
	const SaveLoadFormat *fmt;
  uint version;

	/* An instance of saving is already active, so wait until it is done */
	if (_ts.saveinprogress) {
		if (!_do_autosave) ShowErrorMessage(_error_message, STR_SAVE_STILL_IN_PROGRESS, 0, 0);
		JoinOTTDThread(); // synchronize and wait until save is finished to continue
		// nonsense to do an autosave while we were still saving our game, so skip it
		if (_do_autosave) return SL_OK;
	}

  /* Load a TTDLX or TTDPatch game */
	if (mode == SL_OLD_LOAD) {
		InitializeGame(8, 8); // set a mapsize of 256x256 for TTDPatch games or it might get confused
		if (!LoadOldSaveGame(filename)) return SL_REINIT;
		AfterLoadGame(0);
		return SL_OK;
	}

	_sl.fh = fopen(filename, (mode == SL_SAVE) ? "wb" : "rb");
	if (_sl.fh == NULL) {
		DEBUG(misc, 0) ("Cannot open savegame for saving/loading.");
		return SL_ERROR;
	}

	_sl.bufe = _sl.bufp = NULL;
	_sl.offs_base = 0;
	_sl.int_to_ref_proc = IntToReference;
	_sl.ref_to_int_proc = ReferenceToInt;
	_sl.save = mode;
	_sl.includes = _desc_includes;
	_sl.chs = _chunk_handlers;

	/* XXX - Setup setjmp error handler if an error occurs anywhere deep during
	 * loading/saving execute a longjmp() and continue execution here */
	if (setjmp(_sl.excpt)) {
		AbortSaveLoad();

		// deinitialize compressor.
		_sl.excpt_uninit();

		/* A saver/loader exception!! reinitialize all variables to prevent crash! */
		if (mode == SL_LOAD) {
			ShowInfoF("Load game failed: %s.", _sl.excpt_msg);
			return SL_REINIT;
		} else {
			ShowInfoF("Save game failed: %s.", _sl.excpt_msg);
			return SL_ERROR;
		}
	}

  /* We first initialize here to avoid: "warning: variable `version' might
   * be clobbered by `longjmp' or `vfork'" */
	version = 0;

	/* General tactic is to first save the game to memory, then use an available writer
	 * to write it to file, either in threaded mode if possible, or single-threaded */
	if (mode == SL_SAVE) { /* SAVE game */
		fmt = GetSavegameFormat("memory"); // write to memory

		_sl.write_bytes = fmt->writer;
		_sl.excpt_uninit = fmt->uninit_write;
		if (!fmt->init_write()) {
			DEBUG(misc, 0) ("Initializing writer %s failed.", fmt->name);
			return AbortSaveLoad();
		}

		_sl.version = SAVEGAME_MAJOR_VERSION;

		BeforeSaveGame();
		SlSaveChunks();
		SlWriteFill(); // flush the save buffer

		/* Write to file */
		if (_network_server || !CreateOTTDThread(&SaveFileToDisk, NULL)) {
			DEBUG(misc, 1) ("cannot create savegame thread, reverting to single-threaded mode...");
			SaveFileToDisk(NULL);
		}

	} else { /* LOAD game */
		assert(mode == SL_LOAD);

		if (fread(hdr, sizeof(hdr), 1, _sl.fh) != 1) {
			DEBUG(misc, 0) ("Cannot read savegame header, aborting.");
			return AbortSaveLoad();
		}

		// see if we have any loader for this type.
		for (fmt = _saveload_formats; ; fmt++) {
			/* No loader found, treat as version 0 and use LZO format */
			if (fmt == endof(_saveload_formats)) {
				DEBUG(misc, 0) ("Unknown savegame type, trying to load it as the buggy format.");
				rewind(_sl.fh);
				_sl.version = version = 0;
				_sl.full_version = 0;
				fmt = _saveload_formats + 1; // LZO
				break;
			}

			if (fmt->tag == hdr[0]) {
				// check version number
				version = TO_BE32(hdr[1]) >> 8;

				/* Is the version higher than the current? */
				if (version > SAVEGAME_LOADABLE_VERSION) {
					DEBUG(misc, 0) ("Savegame version invalid.");
					return AbortSaveLoad();
				}

				_sl.version = (version >> 8);
				_sl.full_version = version;
				break;
			}
		}

		_sl.read_bytes = fmt->reader;
		_sl.excpt_uninit = fmt->uninit_read;

		// loader for this savegame type is not implemented?
		if (fmt->init_read == NULL) {
			ShowInfoF("Loader for '%s' is not available.", fmt->name);
			return AbortSaveLoad();
		}

		if (!fmt->init_read()) {
			DEBUG(misc, 0) ("Initializing loader %s failed.", fmt->name);
			return AbortSaveLoad();
		}

		/* Old maps were hardcoded to 256x256 and thus did not contain
		 * any mapsize information. Pre-initialize to 256x256 to not to
		 * confuse old games */
		InitializeGame(8, 8);

		SlLoadChunks();
		fmt->uninit_read();
		fclose(_sl.fh);

		/* After loading fix up savegame for any internal changes that
		* might've occured since then. If it fails, load back the old game */
		if (!AfterLoadGame(version)) return SL_REINIT;
	}

	return SL_OK;
}

/** Do a save when exiting the game (patch option) _patches.autosave_on_exit */
void DoExitSave(void)
{
	char buf[200];
	snprintf(buf, sizeof(buf), "%s%sexit.sav", _path.autosave_dir, PATHSEP);
	SaveOrLoad(buf, SL_SAVE);
}

#if 0
/**
 * Function to get the type of the savegame by looking at the file header.
 * NOTICE: Not used right now, but could be used if extensions of savegames are garbled
 * @param file Savegame to be checked
 * @return SL_OLD_LOAD or SL_LOAD of the file
 */
int GetSavegameType(char *file)
{
	const SaveLoadFormat *fmt;
	uint32 hdr;
	FILE *f;
	int mode = SL_OLD_LOAD;

	f = fopen(file, "rb");
	if (fread(&hdr, sizeof(hdr), 1, f) != 1) {
		printf("Savegame is obsolete or invalid format.\n");
		mode = SL_LOAD; // don't try to get filename, just show name as it is written
	}
	else {
		// see if we have any loader for this type.
		for (fmt = _saveload_formats; fmt != endof(_saveload_formats); fmt++) {
			if (fmt->tag == hdr) {
				mode = SL_LOAD; // new type of savegame
				break;
			}
		}
	}

	fclose(f);
	return mode;
}
#endif